Metabolomic applications in stem cell research: a review

This review describes the use of metabolomics to study stem cell (SC) characteristics and function, excluding SCs in cancer research, suited to a fully dedicated text. The interest in employing metabolomics in SC research has consistently grown and emphasis is, here, given to developments reported in the past five years. This text informs on the existing methodologies and their complementarity regarding the information provided, comprising untargeted/targeted approaches, which couple mass spectrometry or nuclear magnetic resonance spectroscopy with multivariate analysis (and, in some cases, pathway analysis and integration with other omics), and more specific analytical approaches, namely isotope tracing to highlight particular metabolic pathways, or in tandem microscopic strategies to pinpoint characteristics within a single cell. The bulk of this review covers the existing applications in various aspects of mesenchymal SC behavior, followed by pluripotent and neural SCs, with a few reports addressing other SC types. Some of the central ideas investigated comprise the metabolic/biological impacts of different tissue/donor sources and differentiation conditions, including the importance of considering 3D culture environments, mechanical cues and/or media enrichment to guide differentiation into specific lineages. Metabolomic analysis has considered cell endometabolomes and exometabolomes (fingerprinting and footprinting, respectively), having measured both lipid species and polar metabolites involved in a variety of metabolic pathways. This review clearly demonstrates the current enticing promise of metabolomics in significantly contributing towards a deeper knowledge on SC behavior, and the discovery of new biomarkers of SC function with potential translation to in vivo clinical practice.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for co-funding the BIOIMPLANT project (PTDC/BTM-ORG/28835/2017) through the COMPETE2020 program and European Union fund FEDER (POCI-01–0145- FEDER-028835). CSHJ and KR are grateful to the same project for funding their contracts with the University of Aveiro. DSB acknowl- edges the Sociedade Portuguesa de Química and FCT for her PhD grant SFRH/BD/150655/2020. AMG acknowledges the CICECO-Aveiro Institute of Materials project, with references UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Part- nership Agreement. The NMR spectrometer used in this work is part of the National NMR Network (PTNMR) and, partially supported by Infrastructure Project Nº 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC).publishe

An intracellular metabolic signature as a potential donor-independent marker of the osteogenic differentiation of adipose tissue mesenchymal stem cells

This paper describes an untargeted NMR metabolomics study to identify potential intracellular donor-dependent and donor-independent metabolic markers of proliferation and osteogenic differentiation of human adipose mesenchymal stem cells (hAMSCs). The hAMSCs of two donors with distinct proliferating/osteogenic characteristics were fully characterized regarding their polar endometabolome during proliferation and osteogenesis. An 18-metabolites signature (including changes in alanine, aspartate, proline, tyrosine, ATP, and ADP, among others) was suggested to be potentially descriptive of cell proliferation, independently of the donor. In addition, a set of 11 metabolites was proposed to compose a possible donor-independent signature of osteogenesis, mostly involving changes in taurine, glutathione, methylguanidine, adenosine, inosine, uridine, and creatine/phosphocreatine, choline/phosphocholine and ethanolamine/phosphocholine ratios. The proposed signatures were validated for a third donor, although they require further validation in a larger donor cohort. We believe that this proof of concept paves the way to exploit metabolic markers to monitor (and potentially predict) cell proliferation and the osteogenic ability of different donors.publishe

Efeito do armazenamento em diferentes ambientes e embalagens na germinação de sementes de Aroeira-do-Sertão.

Objetivou-se com este trabalho avaliar o comportamento fisiológico das sementes de aroeira-do-sertão (Myracrodruon urundeuva Allemão) armazenadas em diferentes embalagens e ambientes.Edição dos Resumos do V Workshop de Tecnologia e Fisiologia de Sementes e Mudas, Petrolina, dez. 2014

Crescimento inicial de mudas de Aspidosperma pyrifolium irrigadas com água com diferentes níveis de salinidade.

O objetivo do trabalho foi avaliar o efeito da salinidade no crescimento inicial de mudas de Aspidosperma pyrifolium.Edição dos Resumos do V Workshop de Tecnologia e Fisiologia de Sementes e Mudas, Petrolina, dez. 2014

Rainfall, not soil temperature, will limit the seed germination of dry forest species with climate change.

Drylands are predicted to become more arid and saline due to increasing global temperature and drought. Although species from the Caatinga, a Brazilian tropical dry forest, are tolerant to these conditions, the capacity for germination to withstand extreme soil temperature and water deficit associated with climate change remains to be quantified. We aimed to evaluate how germination will be affected under future climate change scenarios of limited water and increased temperature. Seeds of three species were germinated at different temperatures and osmotic potentials. Thermal time and hydrotime model parameters were established and thresholds for germination calculated. Germination performance in 2055 was predicted, by combining temperature and osmotic/salt stress thresholds, considering soil temperature and moisture following rainfall events. The most pessimistic climate scenario predicts an increase of 3.9 °C in soil temperature and 30% decrease in rainfall. Under this scenario, soil temperature is never lower than the minimum and seldomly higher than maximum temperature thresholds for germination. As long as the soil moisture (0.139 cm3 cm3) requirements are met, germination can be achieved in 1 day. According to the base water potential and soil characteristics, the minimum weekly rainfall for germination is estimated to be 17.5 mm. Currently, the required minimum rainfall occurs in 14 weeks of the year but will be reduced to 4 weeks by 2055. This may not be sufficient for seedling recruitment of some species in the natural environment. Thus, in future climate scenarios, rainfall rather than temperature will be extremely limiting for seed germination

Endo- and exometabolome crosstalk in mesenchymal stem cells undergoing osteogenic differentiation

This paper describes, for the first time to our knowledge, a lipidome and exometabolome characterization of osteogenic differentiation for human adipose tissue stem cells (hAMSCs) using nuclear magnetic resonance (NMR) spectroscopy. The holistic nature of NMR enabled the time-course evolution of cholesterol, mono- and polyunsaturated fatty acids (including ω-6 and ω-3 fatty acids), several phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelins, and plasmalogens), and mono- and triglycerides to be followed. Lipid changes occurred almost exclusively between days 1 and 7, followed by a tendency for lipidome stabilization after day 7. On average, phospholipids and longer and more unsaturated fatty acids increased up to day 7, probably related to plasma membrane fluidity. Articulation of lipidome changes with previously reported polar endometabolome profiling and with exometabolome changes reported here in the same cells, enabled important correlations to be established during hAMSC osteogenic differentiation. Our results supported hypotheses related to the dynamics of membrane remodelling, anti-oxidative mechanisms, protein synthesis, and energy metabolism. Importantly, the observation of specific up-taken or excreted metabolites paves the way for the identification of potential osteoinductive metabolites useful for optimized osteogenic protocols.publishe